Some medical diagnostic imaging apparatuses (modalities) such as an X-ray computed tomography (CT) apparatus, a magnetic resonance imaging (MRI) apparatus, an ultrasound diagnostic apparatus, and an X-ray diagnostic apparatus can generate volume data (three-dimensional image data) on the basis of projection data obtained by picking up an image of an object (patient).
The volume data can be used to generate a two-dimensional image (hereinafter referred to as VR image) by volume rendering. The VR image is displayed on a display apparatus to be presented to a user.
Recently, 3D displays that enable a user to recognize a stereoscopic image have started to appear on the market. The 3D displays of this type emit a plurality of parallax component images in different directions. The user can recognize the stereoscopic image as an aggregation of the parallax component images.
Accordingly, VR images are generated by subjecting volume data to volume rendering at different rendering points of view, and the VR images at the plurality of points of view are given to a 3D display as parallax component images, whereby a stereoscopic image corresponding to the volume data can be displayed on the 3D display. A user who looks at the stereoscopic image of this type can recognize a depth direction of the stereoscopic image. Further, the user can recognize a depth direction of even one VR image if shading and texture mapping are performed thereon.
However, it is difficult to move a pointer such as a mouse cursor in a depth direction on a screen. This is because conventional pointers are designed to move two-dimensionally on the screen and movement of the pointers in the depth direction is not taken into consideration in the first place. Accordingly, for example, if a plurality of images are displayed in a superimposed manner in the depth direction, it is difficult to move the pointer between these images.